Browsing by Author "Byalebeka, John"

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Effect of Co-applied Corncob Biochar with Farmyard Manure and NPK Fertilizer on Tropical Soil
(Science Direct, 2021-09) Aporia, Samuel Obeng; Byalebeka, John; Murongo, Marius; Ssekandi, Joseph; Noel, Gordon Logura
Biochar has shown a positive impact on degraded soils. However, the effect of co-applied biochar with farmyard manure and inorganic fertilizer on soil chemical characteristics, yield, nutrient constituent and economic analysis of cucumber did not receive adequate research attention in sub-Saharan Africa. A field experiment was conducted on sandy clay loam soil with biochar at 10 t/ha individually or combined with farmyard manure and NPK using cucumber as a test crop. The co-applied biochar with the 5t/ha farmyard manure and NPK significantly increased soil pH, total nitrogen, available phosphorus, total organic carbon and effective cation exchangeable capacity than the sole application of the NPK fertilizer and the farmyard manure. Cucumber yield, net income, nutrient content such as nitrogen, phosphorus and potassium were significantly higher in the co-applied biochar with farmyard manure and NPK than the sole application of the NPK and the manure. Co-applied biochar with inorganic NPK showed higher soil available phosphorus, nitrogen, cucumber yield and net income than the co-applied biochar with farmyard manure. Similarly, co-applied biochar with NPK plots observed higher macronutrient constituents than the co-applied biochar with farmyard manure. These findings revealed that combined biochar with NPK proved to be an effective reclamation strategy to improve low fertile soils in the tropics than the co-applied biochar with farmyard manure.
Effect of sisal (Agave Sisalana) and sweet thorn (Acacia Karroo) ethno-medicinal extracts on prevalence of selected pests and diseases in assila F1 tomato Variety
(Ecological Organic Agriculture - Growing Sustainability, 2023-03-30) Maganda, Farouk; Acero, Miria; Byalebeka, John; Ssekandi, Joseph; Murongo, Marius Fabian
Introduction - This study compared the efficacy of sisal (Agave sisalana) and sweet thorn (Acacia karroo)ethno-medicinal extracts on prevalence of selected pests and diseases in Assila F1 tomato variety was carried out in order to provide cheap and safe alternative in controlling tomato pests and diseases. Methodology - A 13x13m complete randomized block design with nine replicates was used to determine the prevalence of tomato pests and diseases. The assessment was done at organic demonstration site of Uganda martyrs university using three treatments; sisal extracts, sweet thorn extracts and control. Healthy tender leaves of sisal and sweet thorn were harvested and 10kgs of each treatment were measured and chopped into small piece, crushed then 5litres water was added. The prepared mixtures were then shaken and sprayed uniformly onto the tomato plants in the plots to which they were assigned to at a 4 days interval starting from one to eight weeks 8interval after transplanting for 8 times. Meanwhile control plants were not sprayed. Each replicate had 20 plants and 10 plants were selected for data collection in each replicate. Agronomic traits were evaluated by measuring plant height, stem girth,leaf length,leaf width, leaf length using ametre rule. Final fruit yield was measured by weighing mature tomatoestomatoes. Pests were assessed as follows; whiteflies were assessed by counting the adult white flies. Aphids were assessed using a pest scoring scale of 0-5;African bollow worm is assessed using a scoring scale of 1-5. Disease severity was assessed as below; early blight and late blight severity was assessed using ascale of 1-4 .Bacterial spot severity was scored using the scale of 1-6 and then powdery mildew severity was estimated using a disease scoring scale of 0-5. The analysis of variance (ANOVA) at(P<0.05) was carried and means were compared using LSD. Results & Discussion - The results of the study indicated thet there was significant (P<0.05)diferences recorded between sisal and sweet thorn ethno medicinal extracts for pest prevalence. The lower mean for white flies (0.78), tomato fruit borer (1.3) and aphids (0.86) and red spider mites(0.3) prevalenece score were recorded for sisal ethno medicinal extracts than sweet thorn extracts but lower than the control plots. There was significant differences (P<0.05) observed between of application of sisal and sweet thorn ethno medicinal extracts for disease prevalence. The lower mean for early blight (1.1), late blight (1.6), bacterial spot (1.1)and powedery mildew severity (1.8) severity scores were recorded for sweet thorn ethno-medicinal extracts than sisal extracts but lower than the control plots. The results of the study revealed that application of sisal extracts significantly (P<0.05) increased plant height, stem girth, leaf length, leaf width and final fruit yield. Application of sisal and sweet thorn ethno- medicinal extracts significantly (P<0.05) showed an effect on the yield components and yield of tomatoes. The higher final
Low cost maize stover biochar as an alternative to inorganic fertilizer for improvement of soil chemical properties, growth and yield of tomatoes on degraded soil of Northern Uganda
(Springer Nature, 2023-10-07) Wacal, Cosmas; Basalirwa, Daniel; Byalebeka, John; Tsubo, Mitsuri; Nishihara, Eiji
Soil fertility decline due to nutrient mining coupled with low inorganic fertilizer usage is a major cause of low crop yields across sub-Saharan Africa. Recently, biochar potential to improve soil fertility has gained significant attention but there are limited studies on the use of biochar as an alternative to inorganic fertilizers. In this study, we determined the effect of maize stover biochar without inorganic fertilizers on soil chemical properties, growth and yield of tomatoes (Solanum lycopersicum L.). A field experiment was conducted in 2022 for two consecutive seasons in Northern Uganda. The experiment included five treatments; inorganic fertilizer (control), biochar applied at rates of 3.5, 6.9, 13.8 and 27.6 t ha-1. In this study, maize stover biochar improved all the soil chemical properties. Compared to the control, pH significantly increased by 27% in the 27.6 t ha-1 while total N increased by 35.6% in the 13.8 t ha-1. Although P was significantly low in the 3.5 t ha-1, 6.9 t ha-1 and 13.8 t ha-1, it increased by 3.9% in the 27.6 t ha-1. Exchangeable K was significantly increased by 42.7% and 56.7% in the 13.8 t ha-1 and 27.6 t ha-1 respectively. Exchangeable Ca and Mg were also higher in the biochar treatment than the control. Results also showed that plant height, shoot weight, and all yield parameters were significantly higher in the inorganic fertilizer treatment than in the 3.5, 6.9, and 13.8 t ha-1 treatments. Interestingly, maize stover biochar at 27. 6 t ha-1 increased fruit yield by 16.1% compared to the control suggesting it could be used as an alternative to inorganic fertilizer. Maize stover biochar applied at 27.6 t ha-1 improved soil chemical properties especially pH, N, P and K promoting growth and yield of tomatoes. Therefore, maize stover biochar could be recommended as an alternative to expensive inorganic fertilizers for tomato production in Northern Uganda.
Low Input Approaches for Soil Fertility Management in Semiarid Eastern Uganda
(American Society of Agronomy, 2007) Kaizzi, C. Kayuki; Byalebeka, John; Wortmann, S. Charles; Mamo, Martha
Grain sorghum [Sorghum bicolor (L.) Moench] is an important food crop of semiarid sub-Saharan Africa. Crop yields are generally low, partly due to low soil fertility. Research was conducted with farmers to evaluate, soil fertility management practices in sorghum-based cropping systems including: mucuna [Mucuna pruriens (L.) DC.] fallow; cowpea [Vigna unguiculata (L.) Walp.] rotation with sorghum; animal manure application; N and P fertilizer application; and reduced tillage. Four studies, comprised of 142 on-farm trials, were conducted at three locations over 3 yr in drought-prone parts of eastern Uganda. Mucuna on average produced 7 Mg ha21 of aboveground dry matter containing 160 kg N ha21 across the three locations. Application of 2.5 Mg ha21 of manure and of 30 kg N plus 10 kg P ha21 increased grain yield by 1.05 and 1.30 Mg ha21, respectively. A combination of 2.5 Mg ha21 manure with 30 kg N ha21 increased grain yield by 1.50 Mg ha21 above the control (1.1 Mg ha21). The increase in sorghum grain yield in response to 30 kg N ha21 alone, to a mucuna fallow, and to a rotation with cowpea was 1.15, 1.55, and 0.82 Mg ha21, respectively. These soil fertility management practices, as well as reduced tillage, were found to be cost effective in increasing sorghum yield in the predominantly smallholder agriculture where inorganic fertilizer was not used much. On-farm profitability and food security for sorghum production systems can be improved by use of inorganic fertilizers, manure, mucuna fallow, sorghum–cowpea rotation, and reduced tillage. GRAIN SORGHUM is an important
Maize Response to Fertilizer and Nitrogen Use Efficiency in Uganda
(American Society of Agronomy, 2012) Kaizzi, C. Kayuki; Byalebeka, John; Semalulu, Onesmus; Alou, Isaac; Zimwanguyizza, Williams; Nansamba, Angella; Musinguzi, Patrick; Ebanyat, Peter; Hyuha, Theodore; Wortmann, S. Charles
Maize (Zea mays L.) is an important smallholder crop in Uganda. Yields are low because of low soil fertility and little fertilizer use. Yield response to nutrient application and economically optimal rates (EOxR, where x = N, P, or K) and N use effi ciency (NUE) were evaluated. Twenty-two trials were conducted in four agroecological zones. Yield was consistently increased with N application. Mean maize yield with no N applied (N0) was 1.79 Mg ha–1 and increased by 120% with N application. Mean EONRs were 45 to 24 kg ha–1 N with fertilizer use cost to grain price ratios (CPs) of 10 to 30. With N applied, the mean increase in yield due to P application was 0.28 Mg ha–1 and mean EOPRs were 9 to 1 kg ha–1 P with CPs of 10 to 50. Yield was not increased with K application. Profi tability was greater for N than P application. Mean aboveground biomass N with 0 and 150 kg ha–1 N applied was 46.3 and 94.3 kg ha–1, respectively. Mean N concentration and N harvest index at the EONR were 1.60 and 63.8%, respectively, and higher than for N0. Mean recovery effi ciency, partial factor productivity, and agronomic effi ciency declined with increasing N rate and were 66%, 86 kg kg–1, and 41 kg kg–1, respectively, at the EONR. Fertilizer N use can be very profi table, with high NUE, for smallholder maize production in Uganda, and the fi nancial capacity of smallholders to use fertilizer will increase with reduced CP
Moringa Oleifera Seeds as a Low-cost Biosorbent for Removing Heavy Metals from Waste Water
(University PIM, Banja Luka, 2020-05) Obeng Apori, Samuel; Atiah, Kofi; Hanyabui, Emmanuel; Byalebeka, John
Heavy metals are considered to be one of the major contaminants of water in recent years due to their non-biodegradable property; hence making them toxic and bioaccumulate to living organisms. Conventional methods such us chemical precipitation, physical treatment through ion exchangeare used for removing heavy metal ions from water. These methods are expensive and attributed to incomplete metals removal and high cost of treatment. In recent years, researchers have found alternative low cost and effective method for remova lof toxic metals through biosorption process using biologicalmaterials. Moringa oleifera seeds is oneof the biological materials which has effective adsorption capacity for removal of heavy metals from water and wastewater.In this article, the seeds of Moringa oleifera seeds as a low-cost biosorbent for removal of heavy metals is presented.Moringa oleifera seeds is inexpensive material that contains amino acids. The amino acid is a major constituent of the functional groups that aids in greater ability of heavy metals removal through metal ion exchange or complexation, which is mainly affected by pH, biosorbent dosage, and contact time. Moringa oleifera seeds residues have a greater capacity to absorb heavy metals in a single solution compared to multi ion solution.
Optimizing Smallholder Returns to Fertilizer Use: Bean, Soybean and Groundnut
(2011) Byalebeka, John; Kayuki, Kaizzi C.; Semalulu, Onesmus; Alou, Isaac Newton; Zimwanguyizza, Williams; Nansamba, Angella; Odama, Emmanuel; Musinguzi, Patrick; Ebanyat, Peter; Hyuha, Theodore; Kasharu, Appollo K.; Wortmann, Charles S.
Smallholder African farmers commonly lack the financial means to purchase enough fertilizer for application at the economical optimal rates (EOR), or the rates for maximization of net returns ha−1, to all of their land. Research was conducted for bean (Phaseolus vulgarisL.), soybean (Glycine maxL.) and groundnut (Arachis hypogaeaL.) to establish a basis for determining the combinations of crops, nutrients, and application rates to optimize net returns to fertilizer use and the benefit:cost ratio (BC) in Uganda. Yield response to nutrient application, EORs, and equations for estimating BC were determined. Eleven to 17 trials were conducted for each crop. Mean yields were increased by 92%, 111%, and 92% for N applied to bean, and P applied to soybean and groundnut, respectively, at 15kgha−1, with less yield responses for P applied to bean and K applied to soybean and groundnut. Mean yield peaked at 1.81, 1.92, and 1.71Mgha−1for bean, soybean, and groundnut, respectively. Mean EOR varied with fertilizer cost relative to grain price (CP) and were 27–42kgha−1N for bean, and 13–29kgha−1P with higher rates for groundnut compared with bean. The greatest BC was for N applied to bean followed, in decreasing order, by P applied to soybean or groundnut, P applied to bean, and K applied to groundnut or soybean. Consideration of the six sets of crop–nutrient response functions developed enables optimization of smallholder investment in fertilizer by identifying the crop, nutrient, and application rate combinations that maximize net returns on investments in fertilizer use. This approach is applicable for smallholder crop production globally where farmers cannot purchase enough fertilizer to apply at EOR.We studied fertilizer response for bean, soybean, and groundnut in Uganda. Smallholders often have little money for fertilizer. They need to optimize returns on their small investment. Returns were highest for N applied to bean and P applied to soybean and groundnut. Information is given for selecting crop/nutrient/rate combinations for high net returns. This gave 100% more net return compared with maximizing net returns per hectare. The methodology is adaptable to smallholder farming situations globally.
Phosphorus Sorption in Tropical Soils
(AIMS Press, 2020-09) Hanyabui, Emmanuel; Obeng Apori, Samuel; Agyei Frimpong, Kwame; Atiah, Kofi; Abindaw, Thomas; Ali, Muhammed; Yeboah Asiamah, Joshua; Byalebeka, John
Phosphorus is an important primary nutrient required by plants in large quantities. The various forms of P that plants can take up are the primary monobasic phosphate ion (H2PO4−), secondary dibasic phosphate ion (HPO42−) and phosphate ion (PO43−). In tropical soils, phosphorus adsorption is a major process that controls its availability to crops.Soils with low phosphorus adsorption capacity are often unable to supply adequate phosphorus to the growing crops thereby affecting their yields.This paper reviews the phosphorus adsorption phenomenon in a tropical soil. The review showed that Langmuir isotherm, Freundlich isotherm, Brunauer-Emmett-Teller (BET) isotherm, Dubinin-Radushkevich, and Temkin isotherm are the mostly used isotherms models for describing phosphorus adsorption. From the review, soil acidity and alkalinity,soil temperature and the electrical potential of clay surface are the main factors influencing phosphorus adsorption. Also, precipitation was discovered to be the main mechanism of P adsorption in tropical soils.Fertilization practices such as the addition of organic manure, crop residues, rock phosphate, water-soluble P fertilizers and incorporation of phosphorus solubilizing organism are highly recommended to increase P solubility and availability in highly weathered soil.
Potential of Termite Mounds and its Surrounding Soils as Soil Amendments in Smallholder Farms in Central Uganda
(BMC Research Notes, 2020) Obeng Apori, Samuel; Murongo, Marius; Hanyabui, Emmanuel; Atiah, Kofi; Byalebeka, John
The low fertility of highly weathered soils has been a major problem for resource-constrained small-holder farmers. In central Uganda, smallholder farmers have been collecting termite mound soils anywhere around the termite mound to improve their soil fertility. However, no studies have been conducted on which sections of the termite mounds consist of high soil nutrients. This study was conducted to assess selected major soil essential plant nutrients of soils collected from the top of the mound (TPMS), and the basal part of the mound (BPMS). The surrounding soil samples were collected from five, fifteen, and thirty meters away from the mound (TMSS1, TMSS2, and TMSS3 respectively), covering ten termite mounds in five different maize fields in central Uganda.Results:TPMS and BPMS had significant (P-value < 0.05) higher N, P, K, OC, Ca and Mg levels than TMSS1, TMSS2, and TMSS3. However, OC levels in BPMS was higher than TPMS. On the whole, termite mounds are beneficial as a source for essential plant nutrients. It will be best if smallholder farmers could collect the termite mound soils from the top and the basal part of the mound to improve the fertility of their soil.
Roles for Herbaceous and Grain Legumes, Kraal Manure, and Inorganic Fertilizers for Soil Fertility Management in Eastern Ugand
(Springer, 2011) Byalebeka, John; Kaizzi, K. C.; Wortman, C. S.; Mamo, M.
Grain sorghum [Sorghum bicolor (L.) Moenich] is an important food crop in semi-arid areas of sub-Saharan Africa. Crop yields are generally low and declining partly due to low soil fertility. Therefore on-farm research was conducted on 108 farms at three locations over 3 years to evaluate alternative low-input strategies for soil fertility improvement in sorghum-based cropping systems. The strategies were use of herbaceous legumes in improved fallow, a grain legume in rotation with sorghum, use of cattle manure, and application of low levels of N and P fertilizers. Mucuna (Mucuna pruriens) on average produced 7 t ha–1 of aboveground dry matter containing 160 kg N ha–1. Application of 2.5 t ha–1 of kraal manure and a combination of 30 kg N and 10 kg P ha–1 both increased grain yield by a mean of 1.15 t ha–1. A combination of 2.5 t ha–1 manure with 30 kg N ha–1 increased grain yield by 1.4 t ha–1 above the farmer practice (1.1 t ha–1 grain). The increase in sorghum grain yield in response to 30 kg N ha–1, to a Mucuna fallow, and to a rotation with cowpea (Vigna unguiculata) was 1.0, 1.4, and 0.7 t ha–1, respectively. These alternative strategies were found to be cost-effective in increasing sorghum yield in the predominantly smallholder agriculture where inorganic fertilizer is not used. Results of the study indicated that on-farm profitability and food security could be improved through integration of inorganic fertilizers, herbicides, manure, Mucuna fallow, and cowpea rotation into grain sorghum cropping systems.
Sorghum Response to Fertilizer and Nitrogen Use Efficiency in Uganda
(American Society of Agronomy, 2012) Kaizzi, C. Kayuki; Byalebeka, John; Semaluluo, Onesmus; Alou, Isaac; Zimwanguyizza, Williams; Nansamba, Angella; Musinguzi, Patrick; Ebanyat, Peter; Hyuha, Theodore; Wortmann, S. Charles
Sorghum [Sorghum bicolor (L.) Moench] is important for smallholder production in semiarid parts of Uganda. Grain yields are low because of low soil fertility. Little fertilizer is used. Yield response to N, P, and K application, economically optimal rates for N, P, and K (EONR, EOPR, and EOKR, respectively), and N use effi ciency (NUE) were evaluated at 11 site-seasons. Mean sorghum yield with no N applied (N0) was 0.69 Mg ha–1 and was consistently increased by a mean of 230% with N application. Mean EONRs were 34 to 18 kg ha–1 N with fertilizer use cost to grain price ratios (CPs) of 10 to 30, respectively. Mean EOPRs were 11 to 2 kg ha–1 P with CPs of 10 to 50, respectively. Sorghum did not respond to K application. Net economic returns were greater for N than P application. Mean aboveground biomass N with 0 and 90 kg ha–1 N applied was 31.3 and 75.9 kg ha–1, respectively. Grain N concentration, N harvest index, and internal NUE at the EONR were 1.67%, 53.2%, and 31.8 kg kg–1, respectively, and higher than for N0. Mean recovery effi ciency, partial factor productivity, and agronomic effi ciency declined with increased N rate and were 135%, 79 kg kg–1, and 52 kg kg–1, respectively, at the EONR. Th e profi t potential of fertilizer N use is high for smallholder sorghum production in Uganda. Policy interventions to reduce fertilizer cost and improve grain marketing effi ciency will enable smallholders to increase fertilizer use for substantial increases in sorghum production.